Identification of key aromas of Chinese muskmelon and study of their formation mechanisms

Abstract

The volatile compounds found in melons (Cucumis melo L.) obtained from three cultivars [Jiashi (JS), Xizhoumi17 (XZM) and Minqin (MQ)] were comprehensively analyzed by gas chromatography−olfactometry (GC–O), gas chromatography−mass spectrometry (GC–MS), and GC-flame photometric detection (GC-FPD). The result showed that 46, 45 and 69 volatile compounds were detected in XZM, JS and MQ samples by GC–MS, respectively. Besides, 6, 8 and 9 sulfur compounds were detected by GC-FPD, respectively. Dimethyl sulfide, 1-propanethiol, 3-mercapto-3methylbutanol, 3-methyl-2-buten-1-thiol were detected for the first time in melon. 25 key aroma compounds were identified in MQ muskmelon by omission tests, among which (Z)-6-nonenal, (Z)-6-nonen-1-ol, 3-methylbutanal, 2-methylbutyl acetate, hexanal and methyl thioacetate were particularly important. The interaction between three aroma compounds containing nine-carbon straight-chain structure and five thioesters in MQ muskmelon was studied by comparing their olfactory threshold and OAV values. Among the 18 binary mixtures, 8 mixtures showed a synergistic effect, 2 mixtures presented an additive effect, 2 mixtures showed no interaction, 6 mixtures exhibited a masking effect. There is a synergistic effect between (Z)-6-nonenal, (Z)-6-nonen-1-ol and (E, Z)-3,6-nonadien-1-ol, the aroma intensity of the mixture can be predicted by modified vector model.